Not long ago, at-home health tests were only for pregnancy and g­lucose monitoring. But advances in understanding of the human genome have opened the door to a wide-reaching array of DNA tests. And the shrinking number of medical providers has contributed to the explosion in the number of home tests available to detect chronic conditions that we used to rely on office visits to pick up. There are at-home tests for everything from cholesterol to testosterone now.

But beware: With many tests, you could be wading into murky waters. Patient advocate and longtime Bottom Line Personal contributor David Sherer, MD, says to proceed with caution…

The Good, the Bad …the Inaccurate

There are advantages and disadvantages to at-home tests.

On the positive side…

You don’t have to go to a doctor. These days, seeing a doctor could involve waiting months for an appointment. At-home tests are especially helpful for people living in areas where there are doctor shortages. Keep in mind, though—only a limited number of at-home tests can be done entirely from home…the more common scenario is to purchase a test online and go to a lab for a blood draw.

You can test or prescreen if you’re at risk for certain conditions—perhaps heart disease runs in your family. Testing before any symptoms develop allows you to get ahead on the treatment curve.

You can monitor chronic conditions with fewer doctor and lab ­visits. Certain home tests, such as measuring your blood pressure with a cuff and monitoring blood glucose, can help you make adjustments in diet and exercise or talk to your doctor about changes in a treatment plan.

On the negative side…

You can get false-positives or false-negatives, especially from tests that haven’t been approved by the FDA or if a test kit wasn’t handled properly. Results also may be inaccurate because of timing. Example: If you think you were exposed to HIV and test yourself for antibodies sooner than three to six months after exposure, you could get a false-negative. Also, it can be confusing to do a home test accurately—some people find it hard to do a finger prick for a blood sample and do not get enough blood.

Some tests give an incomplete picture of disease risk. Examples: Many tests for BRCA gene mutations—which indicate risk for breast cancer—check for only the three most common mutations even though there are thousands of possible ones. Some cholesterol tests measure only total cholesterol, which can be misleading.

You might misinterpret the results of any test—positive or negative. It is always best to review your results with your medical provider, who can compare them to past results.

Your privacy could be at risk if the testing company enters your results into a database that could be compromised. Always read through all disclosures on the testing company’s website, and limit what it can do with your results.

You have to pay for them. With the exception of the COVID-19 test, which is reimbursable, at-home tests are not covered by insurance, though you may be able to use FSA or HSA dollars.

To Get the Right Results

Careful research can help you avoid many of the disadvantages listed above…

Buy only FDA-approved tests. Many at-home tests are “lab-developed tests” (LDTs), which are not FDA-approved. If a test has been approved by the FDA, it’s likely to say so on the package and the company website. A Goggle search should let you know for sure.

Look for companies that work with, or are themselves, a well-known lab—such as Quest Diagnostics or Labcorp. There should be a phone number that you can call with questions or to get online help with how to do the test. For some companies, like those mentioned here, test requests and results are reviewed by an independent physician who you might be able to speak with.

Beware of surprising consequences of your results. Though the cost of at-home tests aren’t typically reimbursed by insurance, you should call your plan administrator to find out if your results might impact your coverage in any way. Example: If a genetic test shows that you have a BRCA gene mutation, will your insurance accept the result and cover more frequent mammograms?

Read the directions once…twice…three times. Test accuracy depends on the manufacturer’s ability to produce a quality test and your ability to do the test correctly. Even something as common as blood sugar testing can be inaccurate if you don’t prick your finger as directed. People with diabetes: The FDA recently cleared the POGO Automatic Blood Glucose Monitoring System, the first one-step monitor—you place your fingertip on the pad of the device, and a built-in lancet and the device do the rest.

Don’t decipher the next steps on your own. A doctor should interpret your results and review them with you. Also: Because of liability factors, he/she may insist on repeating the test—this also will reassure you that the results are accurate.

Caution: Test results for life-altering diseases such as HIV or a genetic mutation for cancer can be emotionally ­devastating. It’s crucial to have the proper interpretation and care from a medical professional.

Understand the test’s limitations. Examples: Cologuard can pick up certain markers for cancer, but it’s not a substitute for a colonoscopy, especially for people at high risk. Many cholesterol tests give only your total cholesterol count, but you need to know the breakdown of LDL, HDL, the ratio and triglycerides to determine whether your numbers are in the safe zone. Look for an FDA-approved “complete lipid panel test,” such as the one from Solana Health.

Genetic tests, which were started to help people learn more about their heritage, have expanded into assessing risk for certain illnesses, perhaps based on family history. But this isn’t something you should leave to home testing.

Be wary of tests with dubious ­science behind them. Some types of tests are simply of unproven value. Example: DNA testing to uncover the best diet for you based on your genes (a twist on the 1990s’ fad of eating according to your blood type, a concept that was completely debunked). A study on this topic, published in JAMA in 2018, found no association between a person’s genotype and whether he/she would have success on either a low-carb or low-fat diet.

Also be wary about at-home testing for diet sensitivities and allergies. Non-FDA tests may give you faulty results, and if you stop eating certain food groups based on incorrect information, you could end up with a nutrient deficiency.

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